get_path_lengths: Get Path Lengths

In nhdplusTools: NHDPlus Tools

Get Path Lengths

Description

Given a network and set of IDs, finds path lengths between all identified flowpath outlets. This algorithm finds distance between outlets regardless of flow direction.

Usage

get_path_lengths(outlets, network, cores = 1, status = FALSE)

Arguments

outlets	vector of IDs from data.frame
network	data.frame with ID, toID, and lengthkm attributes.
cores	integer number of cores to use for parallel computation.
status	logical print status and progress bars?

Value

data.frame containing the distance between pairs of network outlets. For a network with one terminal outlet, the data.frame will have 'nrow(network)^2' rows.

Examples

source(system.file("extdata", "walker_data.R", package = "nhdplusTools"))
fline <- walker_flowline

outlets <- c(5329303, 5329357, 5329317, 5329365, 5329435, 5329817)

# Add toCOMID
fline <- nhdplusTools::get_tocomid(fline, add = TRUE)

fl <- dplyr::select(fline, ID = comid, toID = tocomid, lengthkm)

path_lengths <- get_path_lengths(outlets, fl)

outlet_geo <- sf::st_sf(
  dplyr::left_join(data.frame(ID = outlets),
                   dplyr::select(fline, ID = comid), by = "ID"))

sf::st_geometry(outlet_geo) <- sf::st_geometry(nhdplusTools::get_node(outlet_geo))

plot(sf::st_geometry(fl))
plot(sf::st_geometry(outlet_geo), add = TRUE)

nhdplusTools documentation built on Dec. 7, 2022, 5:15 p.m.